Al-Qaeda leader Ayman al-Zawahri called on militant rebel factions in Syria to stop fighting each other and set up a judicial committee to sort out their differences, according to an audio recording released on Islamist websites.

The small but powerful al-Qaeda-linked Islamic State in Iraq and the Levant (ISIL) has been caught up in clashes with other Islamist insurgents in recent weeks, often triggered by disputes over authority and territory.

"Our hearts and the hearts of the (Muslim) nation, which hangs its hopes on you, have bled for the infighting that has spread between the ranks of those waging jihad for Islam," Zawahri said in the five-minute recording.

"We call on all our brothers in all the jihadist groups ... to work towards ending this sedition, which will lead to only God knows what," Zawahri said. (Reuters)